Just a novelty item....in all honesty, not much different from a SBR....you are just short a buttstock.
I haven't experienced a ton of recoil, nor do I have issues with irons. I can hit a steal man sized target at 200yards with irons from a 7.5in upper.
The PWS Diablo is 8.5in and it bangs steal at 300yrds all day long. Though these guns make it out that distance....they still lack muzzle velocity.
The most common way to fire an AR pistol is "cheeking" it. ---> video of cheeking
http://www.youtube.com/watch?v=uL_mlvnw21g
I like to shoulder it and I have no problems doing so.
Your best bet and best results in an AR pistol will be from an upper size known to be reliable in SBRs.....10.5 and beyond.